Some recognizable names from the larger group:

John Brennan - 2 requests
James Clapper - 3 requests
James Comey - 1 request
Samantha Power - 7 requests
Denis McDonough - 1 request
Patrick Conlan - 1 request
Jacob Lew - 2 requests

And...

Joe Biden - 1 request (Jan 12, 2017) https://twitter.com/CBS_Herridge/status/1260635872271228928

Biden unmasked Flynn on the day of the Ignatius WAPO article

McDonough did so on day of Oval Office meeting

A very large number of unmaskings on Dec 15, 2016. Why is this significant?

Clapper signed off on Section 2.3 on this same day. https://www.theepochtimes.com/declassification-raises-further-questions-about-timing-of-obama-data-sharing-order_3315553.html

Section 2.3 was finalized when Attorney General Loretta Lynch signed it on Jan. 3, 2017.

Dec. 14, 15 & 16 seem to have been very popular dates for Flynn unmasking requests...

McCabe not listed. Does not appear to be one the redactions. We know he had transcript.

Which, in some ways, makes the noticeable lack of unmasking requests just on after the date of Flynn's call w/Kislyak all that more significant.

Because there are a lot of questions on this.

To the best of my knowledge, unmaskings pertain to unmasking the identity of a US Citizen on a SPECIFIC piece of intelligence or report.

An unmasking request does not mean that the requesting person than gets everything the NSA has.